Lecture 20 Introduction to PHP (Part-2)€¦ · Introduction to PHP (Part-2) Mr. Mubashir Ali...

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Introduction to PHP (Part-2)

Mr. Mubashir AliLecturer (Dept. of Computer Science)

dr.mubashirali1@gmail.com

Lecture 20

Summary of the previous lecture

• Setting the environment

• Overview of PHP

• Constants and Variables in PHP

Mubashir Ali - Lecturer (Department of Computer Science).

Outline

• Operators in PHP

• Conditional Statements in PHP

• Looping Statements

• Arrays in PHP

1. Operators in PHP

• Arithmetic Operators:

– +, - ,*, /, %

• Assignment Operators:

–+= ($a +=$b ), *= , /=

– .= ($a .= $b)

1. Operators in PHP…

Adds $b in $a

Concatenates $b with $a

• String Operators:

– . , .=

– $a=“abcd”.”efgh”; $a=abcdefgh

– $a.=“ijk”; $a=abcdefghijk

• Increment/decrement Operators:

– ++,--

–$b=$a++

–$b=++$a

First variable

Second variable

Concatenation

Using .=

Variable declared

Incremented before display

Incremented after display

Displaying incremented value

• Logical Operators:

– AND, OR, NOT, XOR

– &&, ||, !

• Equality Operators:

– ==, !=, ===

• Comparison Operators:

– >, <, <=, >=

Integer valueString value

Compares only values

Strict comparison

2. Conditional Statements

• if statement:

if(condition)

• if-else statement:if(condition)

2. Conditional Statements…

• switch statement:switch(variable)

case option:

action

break;

Switch starts

case 0

Case 1

3. Looping Statements

• for loop

• while loop

• do-while loop

• foreach loop

3. Looping Statements

• for loopfor($a=0; $a<10; $a++)

statements

• while loopwhile(condition)

Statements

Increment/decrement

3. Looping Statements…

• do-while loop

Statements

Increment/decrement

While(condition)

• foreach loop

– is used to read an entire array

For loop

While loop

Output from for loop

Output from while loop

Array is declared

Foreach loop starts

Using obtained value

4. Arrays in PHP

• An array is traditionally defined as a group of items that share certain characteristics

• Each item consists of two components:

– the key and a value

• PHP doesn’t require that you assign a size to an array at creation time

• Declaring an array:

– $array-name[key]=value

4. Arrays in PHP…

• Declaring an array:

– $array-name[key]=value

– $players[0]=“Muhammad Yousuf”;

• Adding element in an array:

– $players[1]=“Younus Khan”;

• Accessing element in an array

– echo $players[0];

4. Arrays in PHP…

Declaring array

Adding elements

Foreach loop

4. Arrays in PHP…

• Associative arrays:

– $array-name[‘element-name’]=value

– $players[‘yousuf’]=“Muhammad Yousuf”;

• Adding element in an array:

– $players[‘younus’]=“Younus Khan”;

• Accessing element in an array:

– echo $players[‘yousuf’];

4. Arrays in PHP…

• The array(); can also be used to create an array

– $array_name=array(item_1,item_2,…item_n);

– $players=array(“M.Yoursuf”,”Imran Khan”);

– $players=array(“Yousuf”=>“M.Yoursuf”,”imran”=>”Imran Khan”);

4. Arrays in PHP…

Associative array is created using array()

Accessing elements by name

4. Arrays in PHP…

• Sorting arrays:

– sort()

– rsort()

4. Arrays in PHP…

Array is created

Array is sorted

Array is displayed

4. Arrays in PHP…

rsort() is used

4. Arrays in PHP…

Summary

• Operators in PHP

• Conditional statements

• Looping statements

• Arrays in PHP

References

• Chapter 2, “Beginning PHP6,Apache,Mysql web development” by Matt Doyle, Wroxpublishers, 2009, ISBN: 0470413964

• Chapter 5, “Beginning PHP and MySQL” by W. Jason Gilmore, Apress publisher, 4th edition; 2010, ISBN-13 (electronic): 978-1-4302-3115-8.

Lecture 20 Introduction to PHP (Part-2)€¦ · Introduction to PHP (Part-2) Mr. Mubashir Ali...

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